Concrete substructure-caisson.



1, SPELIVIAN.

CUNCRETE SUBSTRUCTURE CAISSON. APPLICATION FILED DEC. I. I9I3.

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J, SPELMAN. CONCRETE SUBSTHUCTURE CAISSON.

APPLICATION FILED DEC. I, I9I3- Patented Feb. 18, 1919.

2 SHEETS-SHEET 2 iff/7m65.549s

JAMES SPELMAN, 0F MONTREAL, QUEBEC, CANADA. l

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is to provide means by which a substructure caisson may be constructed much lighter and with greatly reduced expense for time, material and form work than at present.

A further object is to provide a structure of this character which will be much lighter and therefore more easily handled than the forms at present inuse.

A still further object is to provide a structure which will have greater buoyancy than the type at present used.

.In the construction of submarine foundations for wharves, piers, revetments or buildings, the present practice is to construct on dry land large caissons of concrete, or reinforced concrete, which when, finished are floated to a position over the desired resting place and then sunk either by filling' the caisson with water or with solid matter. These caissons are usually built with flat walls as shown inFigures 1. and 2. These structures are of course very heavy and when iioated are to a considerable extent submerged, so that there is enormous external' pressure, which under some circumstances increases as the caisson is sunk. This pressure requires that theouter walls be made very strong, and in large structures, also necessitates the use of internal bracing walls. All this additional material greatly adds to the cost and `increases the weight, so that the buoyancy of the completed caisson is very small. In the present invention, these disadvantages are overcome by building up the caisson of a number of cylindrical cells, which owing to their shape are much stronger and do not require the same wall thickness nor any internal bracing. Moreover, the volume of this structure is much- Specification of Letters Patent. Patented FQIL 18, 1919 Application filed December 1, 1913. i

Serial 110.803.994.

than in the ordinary form, so that the structure has greatly increased buoyancy.

In the drawings which illustrate this inventionz- Fig. 1 is a plan view of the of substructure caisson.

Fig. 2 is a vertical transverse section at the center of same.

' Fig. 3 is a view of the improved substructure caisson corresponding to Fig. 1.

Fig. 4f is a vertical transverse view at the center of the caisson shown in Fig. 3.

Fig. 5 is a perspective view showing a completed pier, wharf orthe like, the water and filling being removed in the foreground to show the arrangement of the substructure sections.`

Before referring more particularly to the drawings, it may be stated that the drawings are approximately to scale, the wall thicknslses being as nearly in proportion as poss1 e.

Referring now to the drawings, 11 designates a substructure caisson of the type at present in use, which is particularlya rectangular box having the sides 12, ends 13 and bottom 14 formed integral. When this structure is being floated to the site, the external pressure ofthe water against these flat walls is very great, so that it is necessary to make the walls very thick and strong, and in addition to support them by internal bracing walls 15 and 16, the walls present form 15 being parallel with the side walls 12 and Such great weight would necessitate the sections used being made smaller, so that the stability of the finished structure would be less. -In this invention, the caisson 17 is built up of a number of cylindrical portions 18 integral with one another and with a base 19. This base 19 may be the same width as the base of the caisson 11, but the diameter of the cylindrical lportions need :notibei-as and time for form Work. The improved i substructure caisson; shown in Fig. @3 may be great as the ividthrof-thel caissonmll, asf

clearly shown by comparison of Figs. vl and 3. The circular form of the WallsA enables a much lighter Wall to be used, and yet Withstand the same external pressureas .theuflat Walls 12 and 13. Furthermore, these circulanI walls brace themselves and do not rek-H quire any internal support.

manufactured more cheaply and more quickly than the ordinary form shown in Figi. 1. The flotation` to Vsite will be accompanied by less riskand may be eifected more quickly aslthe body to be moved offers It is impossible to narroWth'eupper part of the caisson 11 and thus reduce the amount of material, for example, by eliminating the side Walls 12 and` increasing .the Walls` 15 Vin thickness and perhaps-spacing them cylindrical structure has the advantage of greater buoyancy. The cylindricall shape which permits Walls of reduced thickness y adds tothis advantage. Inpoint of actual fact, the-heavy base 19 vvhich isplaced under the cylindrical type to give stability to the iinished structure is necessary to ,give stability to the structureduring flotation, as without this great bottom Weight the cylindrically formed .portion would float so high'in the Watertliat itwould readily capsize.- The heavy base, however, makes the structure extremely stable in the Water, and yet allows it to float suiiicientlyhighftobe very sea- Worthy.- On theother hand, the rectangular structure shown in Fig.1, Whichfhas comless resistance. The improved structure will .have for all intents and purposes asgreat stability in the iiished work as the form-shown inf-I `ig..;1.rV In fact, by means of this invention, the subaqueous foundation sections may be inadefvlargerrthan hereto? fore, thus further reducing the `liability of movement, between` the foundation sections;

When the* sections haveV been made,;;the'y are oated to thesite of the-proposedpier-ym either byfilling With-`-Water,or1solid matte-r.V i 'll'iefvvaterv may fbe--introducedA inany suit-- able Way either by opening seacocks]org-by?I pumping into-the caisson.r The=solid inattei may be floated'oution--bargesl-ormaylbe supplied Aby Hdredges ,freine the seafor- Ariver f f bottom.; Each section asfit'-is=oated-..out

is moored or otherwise secured-'over itsl-site-,f

so that it WillsinkeXactlyinto'tlie desired'- position. This course is i' absolutely -iiecessary as it Would be obviously. impractieable Y toinove theseenormous sections afterthey" v have been sunk.- When theL line oli-'caissons substructure is completeg-.the backfilling*- designated 20-is A. put in i and `the-top of the structure finished olf fvvith retaining Wall i 21, which in the case of Wharves,piers-or the`flikemay be provided` with` -a removablev rub paratively little buoyancy, floats 4very 10W t sist'ingjsoi a number of* cylindricalcellsfarranged in a singleirovv itisobviousf-tha-t in the Water andhas greattendency to roll,

so that there is always danger of such a structure filling and sinking Wliileit is being floated `to its site.

In order that the lgreat difference may `bemore completely understood, it may be stated that in tvvocaissons` constructed according'to'Figs. `1 and 8, each `Witha length of 100'feet, a Width of 35 ft.and a depth 'of 39 r ft;, the outer Walls ofthe rectangular form would requireto'be-20 `inches thick,k

and theinner supporting Walls-10l inches including the base would only AWeigh about 1,200 tons.` It ivillibe readily seen Wha-t an enormous saving in material and labor-can be effected bythis means, and also in lumber the substructure, the"retainingffwall-"f21f-fiis generallyff omitted," and; the foundations f placed i directly on rthel substructure,fbutgthis it may `be `found* de'sirableftor arrangel the Y cellsintwofor morefrovvsin plain' or staggeredlrelation. It mayalso be' found-def5' sirable to make thecellsof-any--polygonal forni approximating*ftlrecylindrieal strucl ture;A The-more nearlythisj polygonal struc`- economical the-resultvvillfbe:v While L:forex-Y ternal pressures, cylindrical Wallet ofi plain" concreteyare yquite-sufficient, it may be found necessary gto reinforce the concreteiflif Lthe-f structure is subject to r-any; i-nternalpressure- The base Vmayfialso bereinforecedfto pre 1 vent fracture. The.. form`-ofsubstructure` Y hav-ing a vvide'basefandI narrow gupperpon tionas shown possesses another advantage olf-*stability over -plainrectangular formsgh that is, the center of gravity remains much form thickness, a base ormed integral with nearer the center line of the base if the said cells, the walls of said cells merging structure should become slightly inclined. into each other at their point of contact with This enables sections of this form to bettei` each other. Y

5 withstand any force such as water pressure In witness whereof, I have hereunto set w tending to upset them. my hand in the presence of two witnesses. Having thus described my invention, JAMES SPELMAN. what I claim is Witnesses:

A caisson unit comprising a row of com- S. R. W. ALLEN, l0 plete cylindrical cells having walls of uni- G. M. MORELAND.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington,` D. C. 

